My phone is Spectrum and I’m in Ghana so I want to deactivate it and install sim in it

This sounds like your iPhone is carrier locked to Spectrum's service.

You will need to contact Spectrum and ask them to remove the lock on the phone.

Then, you can contact a carrier in Ghana and have them set up your phone for service.

If your phone is carrier-locked to Spectrum, only Spectrum can release the lock – if they choose to do so.

How to unlock your iPhone for use with a different carrier - Apple Support